1. Field of the Invention
The present invention relates to a system for chemical vapor deposition at ambient temperature using electron cyclotron resonance (ECR) and a method for depositing metal composite film using the same.
2. Description of the Background Art
Generally, there are conventional methods such as an ion beam deposition, a sputter deposition, and a thermal evaporation for forming metal film.
In the ion beam deposition method, a metal is vaporized in a tungsten filament crucible furnace. The metal vapor spouted outward by thermoionic impact forms molecular form or a cluster, and then ionized in an electromagnetic field. The ions are accelerated by an particle accelerator to be impacted on a substrate, and thereby a film is formed.
A film formation mechanism comprises a cluster formation, a nucleation process, and an ad-atom migration. The ion energy in the ion beam ranges largely as eV˜MeV. In addition, the ion energy can be divided into a high energy (MeV), a narrow energy (hundreds of keV˜tens of keV), and a broad beam (hundreds of eV˜a few eV) according to the energy range.
The high energy and the narrow beam having high ion energy are generally used for forming a buried layer of an inorganic film, surface modification, ion injection, or for physical deposition. However, these have high ion energy, and therefore, circumferential temperature rises when the ions are impacted to the substrate to generate many defects, and roughness of an interface and a surface are increased greatly.
The broad beam is usually used for the physical deposition, and the physical vapor deposition can be divided into an ion vapor deposition (IVD), and an ion cluster beam (ICB) according to an ion assisted deposition (IAD) method. The IVD deposits the metal physically as activating the substrate using vapor atom, and the ICB makes the material, which will be deposited, an atom or an ion cluster, and deposits directly by adding energy.
The physical vapor deposition by the ion beam can perform the deposition rapidly and can perform a metal composite film if a plurality of furnaces are used. However, it has some disadvantages as follows.                1) It is difficult to control an amount and a composition of metal included in the film according to a pressure condition in a reactor because the metal is vaporized.        2) Fusion points are different from the kind of the metal, the vaporization speed is differentiated by the temperature in the furnace, and therefore, the metal source which can be used is limited. Also, it is difficult to apply in a successive processes due to the limited size of the furnace.        3) Even in case of the broad beam having lower energy, it is difficult to enlarge due to the problems caused by the focusing of the metal ion.        4) The circumferential temperature is risen by the impact between the accelerated ion of high energy and the substrate to generate many defects, and thereby an interfacial adhesion force is weak and the film is degraded as the time goes by.        5) in case that the substrate is an organic material such as a polymer, the material may be distorted or the physical property of the material may be changed during the process.        
On the other hand, a physical vapor deposition method by a sputter is a technique which etches a metal target using microwave, RF plasma, and DC discharge and physically deposits the ionized metal target on the substrate.
The above technique can deposit simply and rapidly, however, the interface damage is increased and defects are formed on the film, and thereby a mechanical strength or adhesion force between the interfaces is lowered. In addition, the bounding energy is greatly lowered on an upper part of the film because the composition of the film is constituted only of the adhesion of the metal.
A principle of the thermal evaporation is simple, that is, the metal, the compound, or the alloy is heated in a vacuum state to be evaporated from the fusion state, and the evaporated particles are deposited on the substrate. The above method is different from the sputtering method in a point that the evaporation process is the heat exchanging process. The thin film made by the above method is called as vacuum thermal evaporation thin film. Advantages of the vacuum deposition method are as follows. First, a structure of device is relatively simple, second, the vacuum deposition method can be applied to many materials, third, a core growth or thin film growth theory can be easily applied to form the thin film because the thin film formation mechanism is relatively simple, and fourth, it is suitable for in-situ observation of the thin film in forming the thin film because the above method is thermally and electrically simple. Also, fifth, a material having different crystal structure from that of the material of thermodynamical equilibrium or a compound having different composition can be made. However, the above method can be used usually for depositing the material having lower fusion point, there is a limit in the material for evaporation considering the vapor pressure, and the adhesion force of the thin film which is made similarly to the sputtered film is low.
Therefore, in order to maximize the advantages of the vacuum deposition, devices in which the ion beam method and the sputtering method is combined are developed (U.S. Pat. No. 6,214,183). In above device, the ion beam is radiated to a magnetron target to generate a large amount of sputtered particles and secondary ions. However, according to the above device, the ion beam is used only for increasing the function of the sputter, and the fundamental characteristic of the thin film can not be changed.
As described above, in the conventional deposition methods, the characteristic of the deposited film is inferior, and especially, it is not convenient for changing the characteristic of the film. Also, there are some problems such that the deposition is made in high temperature, or the substrate is damaged physically.